Why does the primary productivity in the gulf of Mexico fluctuate over the year?

Primary productivity in the Gulf of Mexico fluctuates seasonally due to variations in sunlight, temperature, and nutrient availability. During spring and summer, increased sunlight and warmer temperatures promote phytoplankton growth, leading to higher productivity. Conversely, in fall and winter, reduced sunlight and cooler temperatures result in decreased productivity. Additionally, nutrient runoff from rivers, particularly during rainfall, can further influence these seasonal changes.